Research

year 1997 
author Sangbok Woo 
Keyword Integrated System, Loading, Tool allocation, Scheduling, Flexible Manufacturing System, Flexibility 
Abstract A Flexible Manufacturing System( FMS ) is an automated manufacturing system which pursues both the productivity of a transfer-line and the flexibility of a job shop simultaneously. In particular, the flexibility of FMS has been recognized as a major element for responding to dynamics of market environment and uncertainties of shop floor. In spite of such an importance, there were few researches which dealt with the effective use of flexibility throughout the production planning and scheduling of FMS. In order to efficiently utilize the flexibility of FMS, it is important to make a pertinent plan for the alternative machines in a given planning horizon. But, this is very complex because we should consider loading and tool-allocation constraints in production planning as well as precedence constraints in scheduling.

There were some researches which divided entire problems into two subproblems - loading and scheduling - and solved them hierarchically. Even a subproblem, however, it is too difficult to find an optimal solution in real time and to establish a relevant goal of the loading problem corresponding with the scheduling performance.

In this thesis, we attempt to solve the loading and scheduling problems of FMS in an integrated manner. So we propose an integrated system and its solution methodologies which can use the flexibility of FMS effectively, and make a decision about tool allocation, machine selection, and sequencing altogether.

The proposed system consists of two main modules, ´schedule generating module´ which makes partial schedules and ´tool-allocation checking module´ which investigates the feasibility of tool-allocation for unscheduled tasks. With interacting two modules, we settle the loading and scheduling problems. In the schedule generating module, we assume FMS scheduling problems as having multiple identical parts and alternative machines. According to characteristics of alternative machines, we classify the schedule generating module into three submodules - identical machines submodule, exclusive machines submodule, and non-identical machines submodule. In the identical machines submodule, we propose an optimal algorithm, a modified nondelay schedule generator which eliminates many duplicating partial schedules not affecting an optimal makespan solution, and show the validity and efficiency of the algorithm by theorems and experiments. In the exclusive machines submodule, we propose some dispatching rules which consider precedence relationships among multiple identical parts, and show the effectiveness of rules by experiments. In the non-identical machines submodule, we propose an schedule generating algorithm which is based on estimated workloads, and some dispatching rules which is devised to efficiently use the non-identical alternative machines, and show the superiority of proposed algorithms and rules by experiments. The schedule generating module can be used independently of the tool-allocation checking module in cases that constraints related to the tool-allocation become meaningless due to the introduction of an automated tool delivery system or a sufficient tool magazine, etc.

In the tool-allocation checking module, we propose a heuristic and a lagrangian relaxation method as well as optimization models. So, it is possible to solve real problems in allowed time limit. The tool-allocation checking module can be used as not only a submodule which solves the loading and scheduling problem, but also a means which indicates the production feasibility of parts selected initially or added in a given tool-allocation status. Experimental results show that in most cases the proposed integrated approach outperforms existing hierarchical approaches in the scheduling performance and the computational time required. In addition to that, the difference between two approaches tends to increase when the number of part types and the number of alternative machines increase and the tool constraints become tight. So, the results show that the proposed approach is very useful for practical problems. 
c PhD 

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번호 c year 제목 author
111 PhD  1995  Design Support System for the Conceptual Design of Manufacturing Databases [13] Kitae Shin 
110 PhD  1991  An Integrated Decision Support System for FMS Planning and Control Problems [11] Seongyoung Jang 
109 PhD  1994  A Study on Design of a Cooperative- Distributed Shop Floor Control System for Computer Integrated Manufacturing [19] Namkyu Park 
108 PhD  1996  An Improved Scheduling Heuristic Based on Batch Splitting Method for The Job Shop Scheduling Problem [4] Hanil Jeong 
107 PhD  1996  A Design Support System for the Process Design of Computer Integrated Manufacturing [2] Chankwon Park 
106 PhD  1997  A Study on the Integration of Process Planning and Scheduling [3] Kidong Kim 
105 PhD  1997  Computer-Aided Synthesis of the Execution Controllers for Workcells in Computer Integrated Manufacturing Systems [18] Sangkyun Kim 
104 PhD  1997  A Study on FMS Design Justification Considering Part Type Selection and Performance Evaluation Hosub Shin 
» PhD  1997  A Study on the Integration of Loading and Scheduling in Flexible Manufacturing Systems [21] Sangbok Woo 
102 PhD  1999  A Study on Job Shop Scheduling Problems considering Production Capacity Adjustment [16] Daeyoung Chung 
101 PhD  1999  A Study on the Manufacturing System State Based Scheduler using Neural Network and Simulator [20] Kitae Kim 
100 PhD  2002  Flexible Job Shop Scheduling with Multi-level Job Structures [16] Yangja Jang 
99 PhD  2003  Process Modeling and Performance Analysis Methodology toward Optimal Design of Manufacturing Systems [30] Kichang Lee 
98 PhD  2004  Ontology Development for e-Business Integration [26] Tai-Woo Chang 
97 PhD  2005  A Study on the Integration of Quality Designing and Process Control in Steel Industry [15] Jonghan Kim 
96 PhD  2005  Performance Analysis and Network Design of Supply Chain for Strategic Decision Making [14] Eoksu Sim 
95 PhD  2005  Development of an algorithm for multi-plant production plans in a supply chain [50] Sungwon Jung 
94 PhD  2008  A study on integrated production planning and strategic framework in supply chain [15] Haejoong Kim 
93 PhD  2009  A Study for Business Process Improvement Using Real-time Information of Unbalanced Work [19] Jaehyun Kong 
92 PhD  2010  Framework for Integrative SRM System and Collaboration Scorecard [26] Jongkyoung Park 
91 PhD  2007  A Study on MRP Process Improvement in a Grid Enabled APS [2] file Hyoung-Gon Lee 
90 PhD  2010  Enhancing Flexibility and Responsiveness in Sales Order Management [54] Mokmin Park 
89 PhD  2013  Price of Simplicity under Congestion: On the Revenue and Pricing Schemes in the Telecommunication Industry [58] file Dongmyung Lee 
88 PhD  2013  A study on production scheduling problems considering differential electricity pricing and distributed generations Jun Young Moon 
87 PhD  2014  Multi-level job scheduling in a flexible discrete-part production environment Hong Bum Na 
86 PhD  2014  A study on integrative decision-making system for reconfigurable manufacturing cells Jin Wu Seo 
85 MS  1994  A Study on Distributed Shop Floor Control of Flexible Manufacturing Systems [4] Daeyoung Chung 
84 MS  1994  A Study on Development of a Knowledge Based Scheduler and Knowledge Acquisition through Simulation [1] Kitae Kim 
83 MS  1995  A Study on knowledge Acquisition for Simulation-based Scheduling Expert System [1] Soohyun Lee 
82 MS  1995  A study on intelligent dispatching strategy in Automated Manufacturing Systems [5] Seongwoo Lee 
81 MS  1988  A Simulation Study on Operating Rules of FMS Considering Tool Change Byunghoon Yoo 
80 MS  1988  Development of a Classification and Coding System through Fuzzy Sets Approach [1] Namkyu Park 
79 MS  1988  A Study on The Machine-Part Group Formation for FMS Planning and Operation Jaeyoon Kim 
78 MS  1989  A Study on the Computer and Database Location of Distributed Computer Systems in FMS [1] Kilsup Yang 
77 MS  1989  An FMS Planning Algorithm Considering Tool Magazine Capacity and Alternative Routings [6] Chankwon Park 
76 MS  1989  A Mathematical Decision Making Model for Real-Time Scheduling of an FMS Jonghan Kim 
75 MS  1995  An Object-Oriented Framework for the Implementation of Distributed Shop Floor Control in FMS [2] Kyungsuk Lee 
74 MS  1995  A study on Real-Time Collection of Shop Floor Data Using Speech Recognition [2] Namjoo Kim 
73 MS  1995  A Study on the Group Scheduling Problem with Sequence-dependent Set-up Times in a Multi-stage Cellular Manufacturing Systems Jaesoo Shim 
72 MS  1990  A Fuzzy Linguistic Approach to the Part Selection Problem in FMS [1] Yoosuk Hong 
71 MS  1990  A Study on Data Allocation Problems for Distributed Database Design [2] Kitae Shin 
70 MS  1991  A Study on Scheduling Problem of Hierarchically Structured Products in FMS [1] Hanil Jeong 
69 MS  1991  A Study on Performance Evaluation of Production Plan for FMS Using Queueing Network [1] Sangbok Woo 
68 MS  1991  A Study on the Layered Architecture for the Control of FMS Cells Hosub Shin 
67 MS  1991  A Study on Image Processing and CAD - Vision System Interface of Manufactured Parts [1] Kidong Kim 
66 MS  1992  A Study on Production Planning Problems in a Flexible Machining and Assembly System [1] Sukang Lee 
65 MS  1992  Event-Driven On-Line Operational Control of Flexible Manufacturing Systems Jonghun Park 
64 MS  1992  A Decision Support System for A Machine Specifications in Design of An FMS [6] Youngkwan Ko 
63 MS  1993  A Study on the Computer-Aided Process Planning for Rotational Parts Considering Machine Status [1] Sungbum Chun 
62 MS  1993  A Comparative Analysis of Production Control Policies under Production Uncertainty [5] Janghan Lee